Examiner



1 6 9 i CROSS REFERENCE liXAit'llNEli United States Patent 0 3 124 472 USE OF 6,6 -ALKYI:IDE )NEBIS(BENZOXAZINES) FOR IMPROVING PHYSICAL PROPERTIES OF CLAYS AND CLAY-CONTAINING SOILS AND COMPOSITIONS RESULTING THEREFROM 5 use of a clay-containing soil Where it exists, except to John Hemwall, g Beach, -9 assigiior to The retire it from agricultural production. Frequently, how- Dow gh m p y, Midland, a corpora ever, the crusting problem with such soils is mitigated by fi 0 De aware the use of cro s which are more capable of penetrating N0 Drawing P 1961 104,784 through crusts} or by planting several seeds together so 10 Clams (CL 10 that by their combined effort at least one plant will This invention concerns compositions and methods for g y transplanting seedlings, in which case the the treatment of clays and clay-containing soils having at Plant does not need to P F crusted Surfaceleast 5 weight percent clay, dry basis, with a 6,6'-alky1i- In many cases these are quite satlsfactory solutions to the denebis(2H-1,3-benzoxazine) compound (hereafter 6,6'- r s problem. In 0ther as s, w r, these t ABB compound) having the formula: nlques impose restrictions on the grower that he would prefer to avoid. The other alternative used, of course, is f" R! to proceed in the hope that conditions necessary to crust 0 O formation do not occur before the plants have penetrated W the soil surface. While this is frequently the case, there are numerous times when it is not, and severe losses to Z V the farmer result. Thus, there is a definite need for clay, clay soils and other clay-containing materials for use as in which R; is a me e of the group consisting of alkyl structural material precursors which, in the presence of arid cycloalkyl groups Containing p to 12 Carbon atQmS; water, have the properties of enhanced dimensional sta- 8 is a member of the group Consisting of H, Cl and bility and of forming less cohesive and adhesive fluid mixa; arid Z is a member of the group Consisting of cyclo' tures, but which, when dried, have the property of less hexyliderie and 3 t0 9 Carbon alkyliderie p The stress resistance than such soils or materials when un- Verition Particularly Concerns treating clays arid clayey treated. Such treated clays, soils and other clay-containsoils for 6 in making SirOrlg arid structurally Stable ing materials can be considered to be less water sensitive roadways and clay-derived structural materials, and for than h Col-responding untreated i l the Controlled fracturing 0t Crust-forming soils in agricul' This invention is concerned with the treatment of clays ture. and clay-containing soils having at least 5 weight percent, Clays and clay-containing materials are found naturald b i f a naturany occurring l leg" f h y in various geological deposits, including soil. These kaolinitic, montmorillonitic, illitic or mixed layer type, materials have the properties of being dimensionally uni h a 6,6'-ABB compound, as specified b i an stable and of forming fiuid cohesive and adhesive mixamount ranging between about 0,0025 and 2 weight pertures in the Presence of Water. Conversely, p y g cent, dry clay basis, to improve their physical properties, these materials become extremely stress resistant. While h h r for structural purposes or for agricultural purmany of the uses of cl y l y SOilS and other y' poses. An auxiliary solidifying or bonding agent such as tairiihg materials depend upon these P p there are 40 lime, asphalts (black to dark brown solid or semisolid several uses for which such properties are a distinct hancementitious hydrocarbons which gradually liquefy when dicap or even acomplete bar. heated, the predominant constituents of which are bi- Thus, when clays and clay-containing soils are used turnens), sodium silicates having a silica to soda ratio as integral constituents of the foundation, grade, base 01' (SiO :Na O) in the range of 1.69:1 to 3.90:1 or Portland structure in the construction of highways, runways, dams cement in amount from 1 to 100 weight percent, clay and buildings, the problem often arises that the claybasis, is advantageous in making structural materials. containing material loses a significant portion of its By way of illustration, the following sorts of 6,6'-ABB strength or load-bearing capacity in the presence of compounds can be used in the practice of this invention: moisture or water. This is true even of materials which have been treated with common solidifying agents such as 2 351? p yhdenebls(3-butyI'34'dlhydro'2H'l3'bgnz' Portland cement or lime. Y

Clay-containing soils which have been exposed to rain ggiggg g or irrigation water and subsequently dried often will form crusts through which plant penetration is very difficult or iggigg g cyCloheXyl'B4 dlhydro'2H-13' impossible.

fIn the past it has been the practice to avoid the 11186 gg i g h chloro dlhydro 0 these clay-containing materials, to compensate for t eir shortcomings by other methods, or to use them in spite ffi i f giiig ig of their shortcomings. Thus, in the construction indus- 66, secibutylidenebis(3 cyclohexyl 34 dihydrO 2H 1,3 try where it IS desired to make use of local 50115 or agbenzoxazine) gregate, the presence of excessive amounts of clay in these I materials has necessitated the hauling in of materials from i gggf i gi 3cyclohexilsA'dlhydro'ZHlJ other locations. This operation is expensive and, furthermore, suitable materials are frequently scarce. Another They may be prepared following procedures shown in alternative has been to process the clay-containing-aggre- U.S. Patent 2,825,728, issued March 4, 1958. gate so as to remove the clay. Again, this is an expensive The 6,6'-ABB compound can be applied to the clay procedure and is not always practical. Other alternative or clay-containing soil in several ways. The preferred procedures involve using engineering techniques such as way involves dispersing the 6,6'-ABB compound either as reinforced concrete, extra thick bases and grades, and pila suspension or as a solution in a liquid medium and ings to compensate for the inferior properties of the clayadmixing the resulting liquid dispersion with the clay or containing materials. are expensive.

These techniques, however, also The final alternative is to maintain conice struction costs at a minimum and to use the inferior claycontaining materials. This, of course, results in increased maintenance costs throughout the years.

For agricultural purposes, it is impossible to avoid the clay-containing material via spraying, slurrying or other suitable methods. Suitable liquids for dispersion have a boiling point up to ca. 150 C. and include water, ketones, alcohols and hydrocarbon solvents, mixtures thereof and emulsions thereof, either oil-in-water or waterin-oil.

Because of the diverse natures of the 6,6'-ABB compounds utilized in the practice of-this invention, some types are soluble, dispersible or emulsifiable in relatively hydrophilic media, others in relatively hydrophobic media. Upon inspection of a chemical formula, the art skilled can generally determine a solvent, dispersion medium or emulsifier satisfactory for a given 6,6-ABB compound. In any event, the operability and desirability of a given solvent, dispersion medium or emulsifying agent can be determined by a simple test wherein a given 6,6'-ABB compound is dissolved, suspended or its solution emulsified in a given medium. Obviously, solvents, diluents and emulsifying agents are used which are inert toward the 6,6'-ABB compound. Hereinafter, such solutions, suspensions and emulsions will sometimes be referred to broadly as dispersions and the solvent, suspension and emulsion media will be referred to broadly as dispersion media. Advantageously, the 6,6-ABB compound dispersion contains between 0.0025 and 50 weight percent of 6,6-ABB compound.

The treatment of the clay or clay-containing soil with the 6,6'-ABB compound should result in the clay or claycontaining soil containing at least 0.0025% and advantageously up to 2% by weight of the 6,6'-ABB compound, dry clay basis. The upper limit is essentially economic. The 6,6-ABB compounds used for agricultural purposes need be applied only to the actual volume of soil being Ycultivated. Thus, when a 6,6-ABB compound is used to decrease soil crusting, it is practical to treat only the soil immediately above the seed row. Depending upon how carefully the 6,6'-.ABB compound is applied to this restricted volume of soil, anywhere from 0.1 pound to pounds of the 6,6-ABB compound is sufiicient to treat one acre of crop land.

The modulus of rupture test (hereafter MR) is a test to determine the maximum stress that a material will withstand without breaking and is determined by subjecting a rectangular briquette to a bending moment. Thistest is commonly accepted by soil scientists as a measure of the crusting potential of a soil and, hence, its relative suitability as an agricultural soil. The lower the maximum stress before rupture, the less the crusting potential of the soil.

The MR was determined on an apparatus patterned after that as described and used by L. A. Richards in the Soil Science Society of America Proceedings, 17: 321-323.

In each experiment conducted to obtain the test data, one control was included. The control was prepared exactly analogously to the other treatments except that no 6,6-ABB compound was used.

The unconfined compressive strength test (hereafter UCS) is a commonly accepted test used by civil engineers to determine the suitability of a soil to resist shear by stresses to which it will be subject.

The UCS test data were obtained with 6,6'-ABB compounds using an unconfined compression testing apparatus manufactured by Soiltest Incorporated, model U-160. The rate of strain on the samples was about 0.07 inch per minute. The maximum stress which the samples could bear prior to failing was used to calculate the UCS of the sample via the method outlined in the manual provided by Soiltest Incorporated, entitled Unconfined Compression Testing of Cohesive Soils, dated 1957.

In each set of determinations conducted to provide the data for the following examples, one control was included. A control was prepared in a manner exactly analogously to the other treatments except that no 6,6'-ABB compound was used.

The following examples describe completely specific embodiments and the best mode contemplated by the inventor for carrying out his invention. They are not to be construed as limiting the invention, which is defined in the claims.

EXAMPLE 1 A series of samples of finely ground, air-dried, slightly acid, clay loam soil was brought up to a moisture content of about 17% by spraying water as a fine mist onto the soil samples while subjecting them to thorough mixing. Various 6,6'-ABB compounds, as indicated in following Table I, were immediately added in series to the soil samples by spraying with and mixing in 5 to 10 ml. of an acetone solution containing 20 mg. of the 6,6'-ABB compound per 100 g. air-dried soil to provide a treated soil containing 200 ppm. of 6,6'-ABB compound on a dry soil weight basis.

Once the soil had been treated, it was allowed to stand in the open air for at least two hours and then was dried in an oven at 30 C. overnight. The heated soil was then divided into replicates of 25 to 30 g. each, the excess being disposed of, and placed into two rectangular molds 3.2 cm. wide by 6.4 cm. long. The soil in the molds was then leveled and compacted with a special compacting tool. The compacting tool has a base which covers the leveled soil sample and onto which was dropped a weight of 31.5 g. from a height of 31.5 cm. This weight was dropped repeatedly for six times, after which the soil was flooded with water. After the excess water had drained through the soil, the samples were dried overnight in an oven at 30 C. The resulting briquettes were then tested by the method cited above for their MR.

MR determination, as described above, were carried out on the treated samples and untreated control with the following results:

6,6 isopropylidenebis(8 chloro 3 cyclohexyl-3,4-dihydro-2H-1,3-benzoxazine) 2400 6,6 isopropylidenebis(3 cyclohexyl 3,4-dihydro-8-methyl-2H-l,3-benzoxazine) 1250 EXAMPLE 2 A series of mixtures of 4 g. quantities of Portland cement intimately mixed with g. quantities of a finely ground, air-dried, slightly acid, clay loam soil were prepared. Each such mixture was then brought up to a moisture content of about 17% by spraying water as a fine mist onto the soil while subjecting the soil to additional mixing. Various 6,6'-ABB compounds, as indicated in following Table II, were immediately added to the soil samples by spraying with and mixing in 4 ml. of an acetone solution containing 80 mg. of the 6,6'-ABB compound. This treatment resulted in the soil containing 5% Portland cement and 0.1% 6,6-ABB compound on a dry soil weight basis.

After the soil samples had been treated, each was placed in a cylindrical molding tube 3 cm. in diameter and compressed from both ends in a hydraulic press at a pressure of 740 psi. until a static condition was attained. Each sample was then immediately ejected from the molding tube and placed in a relative humidity atmosphere to cure for a period of four days, followed by a one-day cure at room humidity. Next, each sample was immersed in water for one day, after which the series was tested for UCS, as described above.

5 Table II 6,6-ABB compound:

Contr 6,6 isopropylidenebis( 3 butyl 3,4 dihydro- UCS in p.s.i. 49

2H 1,3 benzoxazine) 144 6,6 isopropylidenebis(3 dodecyl 3,4 dihydro 2H 1,3 benzoxazine) 111 6,6 isopropylidenebis(3 cyclohexyl 3,4 dihydro 2H 1,3 benzoxazine) 98 6,6'-isopropylidenebis(8-ch1oro 3 cyclohexyl- 3,4 dihydro 2H 1,3 benzoxazine) 80 6,6 isopropylidenebis(3 cyclohexyl 3,4 dihydro 8 methyl 2H 1,3 benzoxazine)..- 179 EXAMPLE 3 MRin 6 6-ABB Com und p millibars GontroL.

6,6-isopropylidenebis(3-buty1-3,4-di.l1ydro-2H- 1,3-benzoxazine) EXAMPLE 4 SOILS USED Moisture Percent pH content at O.M. treatment in percent Mechanical analysis Soil Sand Silt Clay 1 Organic matter.

Table I V-B MR in millibars Soil 6,6-ABE Compound 1 Control 1 6,6-isopropylidenebis(3-butyl-3,4-dihydro-2H-1,3-benzoxazlne) 6 EXAMPLE 5 The procedure of Example 1 was repeated with the indicated 6,6-ABB compounds with the following results:

Table V 6,6-ABB compound: MR in millibars Contr 4900 6,6 cyclohexylidenebis(3 cyclohexyl 2,4-

dihydro 2H 1,3 benzoxazine) 1600 6,6 sec butylidenebis(3 cyclohexyl 3,4-dihydro 2H 1,3 benzoxazine) 2050 EXAMPLE 6 The procedure of Example 2 was repeated using another similar soil with the following 6,6-ABE compounds with the following results:

Table VI 6,6-compound: UCS in p.s.i. Control- 0 6,6 cyclohexylidenebis(3 cyclohexyl 3,4 dihydro 2H 1,3 benzoxazine) 110 6,6 sec butylidenebis(3 cyclohexyl 3,4 dihydro 2H 1,3 benzoxazine) What is claimed is: 1. The method of treatment of clays and clay-containing soils by admixing therewith a compound having the in which R is a member of the group consisting of alkyl and cycloalkyl groups containing up to 12 carbon atoms; R is a member of the group consisting of H, Cl and CH and Z is a member of the group consisting of cyclohexylidene and 3 to 9 carbon alkylidene groups, in amount sufficient to provide at least 0.0025 and up to 2 weight percent of said compound, dry clay basis.

2. A composition of a clay material of the group consisting of clays and clay-containing soils and in admixture therewith at least 0.0025 and up to 2 weight percent. clay basis, of a compound having the formula:

O O millin which R is a member of the group consisting of alkyl and cycloalkyl groups containing up to 12 carbon atoms;-

R is a member of the group consisting of H, Cl and CH and Z is a member of the group consisting of cyclohexylidene and 3 to 9 carbon alkylidene groups.

3. The composition of claim '2 wherein the clay material contains at least 5 weight percent clay, dry basis, and from 1 to weight percent of at least one member of the group consisting of Portland cement, lime, asphalts and sodium silicates, dry clay basis.

4. The composition of claim 2 wherein the compound is 6,6 isopropylidenebis (3 butyl 3,4 dihydro-2H-1,3- benzoxazine).

5. The composition of claim 2 wherein the compound is 6,6-isopropylidenebis(3-dodecyl-3,4-dihydro 2H 1,3- benzoxazine) 6. The composition of claim 2 wherein the compound is 6,6-isopropylidenebis(3-cyclohexyl-3,4-dihydro-2H-l,3- benzoxazine) 7. The composition of claim 2 wherein the compound is 6,6'-isopropylidenebis(8 chloro 3,4 dihydro-2H-l,3- benzoxazine).

8. The composition of claim 2 wherein the compound 7 is 6,6 isopropylidenebis(3 cyclohexyl 3,4 dihydro-8- methyi-2H-1,3-benzoxazine) 9. The composition of claim 2 wherein the compound is 6,6'-sec-butylidenebis(3cyclohexyl-3,4-dihydro-2H-1,3- benzoxazine).

10. The composition of claim 2 wherein the compound is 6,6'-cyclohexylidenebis(3-cyc1ohexyl 3,4 dihydro-ZH- 1,3-benzoxazine) References Cited in the file of this patent UNITED STATES PATENTS 

1. THE METHOD OF TREATMENT OF CLAYS AND CLAY-CONTAINING SOILS BY ADMIXING THEREWITH A COMPOUND HAVING THE FORMULA: 